From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [PATCH 07/10] block: return on congested block device To: Goldwyn Rodrigues , linux-fsdevel@vger.kernel.org Cc: jack@suse.com, hch@infradead.org, linux-block@vger.kernel.org, linux-api@vger.kernel.org, viro@zeniv.linux.org.uk, akpm@linux-foundation.org, Goldwyn Rodrigues References: <20170615160002.17233-1-rgoldwyn@suse.de> <20170615160002.17233-8-rgoldwyn@suse.de> From: Jens Axboe Message-ID: <6e138fe9-ad88-bf94-f0bb-c95d2f3cb705@kernel.dk> Date: Thu, 15 Jun 2017 10:42:58 -0600 MIME-Version: 1.0 In-Reply-To: <20170615160002.17233-8-rgoldwyn@suse.de> Content-Type: text/plain; charset=utf-8 List-ID: On 06/15/2017 09:59 AM, Goldwyn Rodrigues wrote: > From: Goldwyn Rodrigues > > A new bio operation flag REQ_NOWAIT is introduced to identify bio's > orignating from iocb with IOCB_NOWAIT. This flag indicates > to return immediately if a request cannot be made instead > of retrying. > > Stacked devices such as md (the ones with make_request_fn hooks) > currently are not supported because it may block for housekeeping. > For example, an md can have a part of the device suspended. > For this reason, only request based devices are supported. > In the future, this feature will be expanded to stacked devices > by teaching them how to handle the REQ_NOWAIT flags. Looks fine to me now. I don't know what tree will take these patches, but if it's not block, then you can add: Reviewed-by: Jens Axboe -- Jens Axboe